U.S. patent number 4,930,468 [Application Number 07/334,254] was granted by the patent office on 1990-06-05 for ice with single intake valve and dual intake manifold runners.
This patent grant is currently assigned to Ford Motor Company. Invention is credited to William F. Stockhausen.
United States Patent |
4,930,468 |
Stockhausen |
June 5, 1990 |
Ice with single intake valve and dual intake manifold runners
Abstract
An ICE with at least one intake port and intake valve has an air
inlet passage that is split by a divider wall into primary and
secondary runners, the primary being smaller than the secondary.
The secondary contains a flow deactivation valve for shutting off
or permitting flow to the inlet port opening. The divider wall
extends to a point immediately adjacent the intake valve stem so as
to positively divide the passage into the two independent runners.
The centerline of the primary passage is oriented so as to produce
the desired swirl rate to the air flow, other geometric
considerations being defined to accurately control the swirl rate
of flow and velocity to provide maximum efficiency of operation;
one being that the primary passage cross-sectional area be 40%-50%
of the total cross-sectional area of the port opening, another
being that the volume between the closed deactivation valve and the
intake valve being less than 15% of the cylinder displaced volume,
and including other sized ratios.
Inventors: |
Stockhausen; William F.
(Northville, MI) |
Assignee: |
Ford Motor Company (Dearborn,
MI)
|
Family
ID: |
23306346 |
Appl.
No.: |
07/334,254 |
Filed: |
April 6, 1989 |
Current U.S.
Class: |
123/188.14;
123/308 |
Current CPC
Class: |
F02B
31/08 (20130101); F02B 61/045 (20130101); Y02T
10/12 (20130101); F02B 1/04 (20130101); Y02T
10/146 (20130101) |
Current International
Class: |
F02B
61/04 (20060101); F02B 31/08 (20060101); F02B
31/00 (20060101); F02B 61/00 (20060101); F02B
1/00 (20060101); F02B 1/04 (20060101); F02B
031/00 () |
Field of
Search: |
;123/188M,308,306,432,52M |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Dolinar; Andrew M.
Assistant Examiner: Macy; M.
Attorney, Agent or Firm: McCollum; Robert E. Sadler;
Clifford L.
Claims
I claim:
1. An induction system for a multi-cylinder internal combustion
engine having at least one intake valve port opening per cylinder,
a pair of individual primary and secondary intake manifold runners
for each cylinder with each runner connected at one end to an air
inlet and both runners connected at their other ends to the same
cylinder intake valve port opening, the primary runner being
connected to the opening in a manner to effect flow tangentially
thereinto to induce a strong swirl motion to the air/fuel mixture
inducted into the cylinder, an intake valve mounted for movement
into and out of the opening for controlling flow through the same,
the latter valve having a stem projecting upwardly therefrom, and
deactivation valve means variably moveable in each secondary runner
to block or permit air flow therethrough to control the total air
flow to its respective intake port opening, each primary runner
having a cross-sectional area that is approximately 40% to 50% of
the total cross-sectional area of the intake port opening
associated therewith to assure a minimum restriction to flow
assuring sufficient flow volume of air into the cylinder to define
a wide operating range of the engine during flow through only the
primary runner while concurrently providing sufficient swirl
velocity to the air to stabilize combustion and enhance burn rates
of an air/fuel charge inducted into the cylinder through the
opening, and wherein the two runners are defined by a common
partition wall extending longitudinally towards the stem and
laterally, from the floor of the intake air passage, upwardly in
the same direction as the stem to provide two side-by-side
longitudinally extending runners split by the wall.
2. A system as in claim 1, the wall extending longitudinally to and
immediately adjacent the stem to positively split the air flow into
the opening into two paths to control swirl air motion upon the
variable opening and closing of the deactivation valve.
3. A system as in claim 1, the dividing wall extending
longitudinally upstream to at least the location of the
deactivation valve to define a predetermined volume in the
secondary runner between the port opening and the deactivation
valve.
4. A system as in claim 3, wherein the predetermined volume is less
than 15% of the cylinder displaced volume so as not to diminish the
effect of the induction velocity of the air through the primary
runner when the deactivation valve is closed.
5. An induction system for a multi-cylinder internal combustion
engine having at least one intake valve port opening Per cYlinder,
an intake valve reciprocably mounted in the opening and having a
stem projecting outwardly therefrom, an air inlet passage connected
to the opening, the passage containing a wall which extends
upwardly from the floor of the air intake passage dividing the
passage into individual primary and secondary intake manifold
runners with each runner connected at one end to air and both
runners connected at their other ends to the cylinder intake valve
port opening, the wall extending in line with and parallel to the
intake valve stem locating the primary and secondary runners
side-by-side, one end of the wall extending to a point essentially
contiguous to the stem to positively separate the runners, the
primary runner being connected to the opening in a manner to effect
flow tangentially thereinto to induce a strong swirl motion to an
air/fuel mixture adapted to be inducted into the cylinder, and
deactivation valve means variably moveable in each secondary runner
to block or permit air flow therethrough to control the total air
flow to the intake port opening, the primary runner having a
cross-sectional area that is approximately 40% to 50% of the total
cross-sectional area of the intake port opening associated
therewith to assure a minimum restriction to flow assuring
sufficient flow volume of air into the cylinder to define a wide
operating range of the engine during flow through only the primary
runner while concurrently providing sufficient swirl velocity to
the air to stabilize combustion and enhance burn rates of an
air/fuel charge inducted into the cylinder through the opening.
6. A system as in claims 1 or 5, wherein the longitudinal
centerline of the primary runner is located outboard of the
secondary runner with respect to the cylinder bore centerline for
inducing a strong swirling motion to the primary flow into the
cylinder.
7. A system as in claims 1 or 5, wherein that portion of the
partition wall immediately adjacent the valve stem is oriented with
respect to the cylinder bore centerline such that in plan view the
angle formed between a line normal to the centerline of the
partition wall as extended through the center of the intake valve
stem and a second line extending from the cylinder bore center
through the intake valve stem is between 10 and 20 degrees.
8. A system as in claims 1 or 5, wherein the longitudinal
centerline of the end of the primary runner immediately adjacent
the intake valve extended past the intake valve intersects a line
extending from the cylinder bore center through the center of the
intake valve stem out to the cylinder bore, the distance of the
intersection from the cylinder bore center being between 0.75 and
0.85 of the cylinder bore radius.
9. A system as in claims 1 or 5 including a spark plug located
between the cylinder bore and the intake valve in a location such
that the incoming swirling air charge scavenges the electrodes of
exhaust gas residuals to effect optimum initiation of subsequent
combustion.
10. A system as in claim 1, wherein the air inlet is located
upstream of the partition wall splitting the air into primary and
secondary air flow paths, the primary runner having essentially a
constant cross-sectional shape to minimize flow losses resulting
from splitting the flow into the two paths.
11. A system as in claim 5, the dividing wall extending
longitudinally upstream relative to the passage to at least the
location of the deactivation valve to define a predetermined volume
in the secondary runner between the port opening and the
deactivation valve, the predetermined volume being less than 15% of
the cylinder displaced volume so as not to diminish the effect of
the induction velocity of the air through the primary runner when
the deactivation valve is closed.
Description
This invention relates in general to intake manifolding for an
automotive type internal combustion engine. More particularly, it
relates to one in which an intake valve port opening is connected
to an ambient air inlet by a passage that is split into primary and
secondary runners by a wall for controlling flow volume as well as
swirl intensity of an air/fuel charge flowing into the port
opening. The secondary runner contains a flow deactivation valve
for controlling the intensity of the swirl as well as the total air
flow to the intake port opening, the cross-sectional area of the
primary runner and the volume of the secondary runner being tightly
controlled, as is the geometric configuration, to provide optimum
gasoline engine performance at high speed, maximum power, as well
as at low speed, light load conditions.
The use of dual manifolds to control air flow/fuel to a single
intake valve port opening, with the secondary manifold being
controlled by a valve, to control swirl and engine charge burn
rates, is known. For example, U.S. Pat. No. 4,550,699, Okumura et
al, shows an engine with two intake valves, 6a and 6b, each having
dual manifold air inlets, with the secondary passages being
controlled by a rotary control valve. At one point, the secondary
passage appears as large as the primary passage; furthermore, the
secondary passage has a large volume between the deactivation
control valve and the intake port opening which leads to large
engine pumping losses when the valve is closed. No indication is
given of the size of the primary and secondary passages to provide
the flow velocity and volume necessary for the desired swirl.
U.S. Pat. No. 4,543,931, Hitomi et al, shows an engine intake
manifolding system including a horizontally positioned partition
member 14 that divides the manifold into primary and secondary
runners, the secondary runner having a deactivation flow valve 15.
It will be noted that the partition does not extend to the valve
stem and therefore effects a recombination of the air streams in
both channels prior to the intake valve port opening, which
suppresses the generation of swirl. Again, there is no indication
of the relative sizes of the primary and secondary passages to
assure sufficient swirl at low speed, light load conditions, or the
specific geometric configurations also necessary to control the
swirl desired.
U.S. Pat. No. 4,256,062, Schafer, shows primary and secondary
intake manifold runners directing air to an engine intake manifold
port opening, a common wall defining the two runners, and
deactivation valve means to control flow through the runners. In
this case, a large volume of the secondary runner when the
deactivation valve is closed diminishes the effect of the swirl
generated by the primary passage. Also, the small cross-sectional
area of the secondary passage leads to increased engine pumping
losses. Also, the geometric configurations are not indicated that
lead to a design to provide the proper swirl at low speed, light
load conditions.
U.S Pat. No. 4,499,868, Kanda et al, shows primary and secondary
engine intake manifold runners connected to a single intake valve
port opening and defined by a partition or wall 19 and a
deactivation valve in the secondary passage. However, the dividing
wall extends downwardly only a portion of the intake passage and
does not define distinct primary and secondary passages that will
control swirl rate in a desired manner.
From the above, it will be seen that there is no teaching in any of
the references of the specific configuration and cross-sectional
areas and volumes of the various passages to control swirl in a
manner to maximize engine operating efficiency at both maximum and
minimum operating conditions.
Therefore, it is a primary object of the invention to provide an
engine manifolding construction that includes dual manifolding to a
single engine intake valve opening, wherein the cross-sectional
area of the primary passage or runner is between 40%-50% of the
total cross-sectional area of the intake valve port opening for
minimizing engine pumping losses when the deactivation valve is
closed, and wherein the secondary passage volume between the
deactivation valve and the intake port opening is less than 15% of
the cylinder displaced volume so as not to diminish the intensity
of the swirl generated by the primary passage; and wherein other
critical dimensions are provided for effecting the desired amount
of swirl to control engine burn rates.
Other objects, features and advantages of the invention will become
more apparent upon reference to the succeeding, detailed
description thereof, and to the drawings illustrating the preferred
embodiment thereof; wherein:
FIG. 1 is a cross-sectional view, schematically illustrated, of a
portion of an engine embodying the invention;
FIG. 2 is a cross-sectional view taken on a plane indicated by and
viewed in the direction of the arrows 2--2 of FIG. 1;
FIG. 3 is a view similar to FIG. 1;
FIGS. 4 and 5 are views corresponding to FIGS. 1 and 2,
respectively;
FIG. 6 includes multiple cross-sectional views indicated by
corresponding numbers and taken on respective planes indicated by
and viewed in the direction of the corresponding arrows in FIGS. 4
and 5;
FIG. 7 is a chart graphically comparing various engine operating
characteristics with changes in area ratio; and
FIGS. 8 and 9 are further graphical illustrations comparing intake
valve lift with engine air/fuel swirl and flow rates.
FIG. 1 illustrates schematically a portion of an automotive type
internal combustion engine. It includes a cylinder block 10 having
a bore 12 within which is reciprocably mounted a piston 14.
Attached to the block is a conventional cylinder head 16 having a
recessed portion defining a combustion chamber 18 and the usual
intake and exhaust valves 20 and 22. The latter are mounted for
reciprocation between open and closed positions for controlling
flow through the port openings 24 and 26, respectively. Each of the
valves includes the usual head 28 and a stem 30.
As best seen in FIG. 1, the intake valve port opening is connected
to ambient air by means of a passage 32 that contains a vertically
extending partition or wall 34. The latter splits the passage 32
into two side-by-side manifold runners, a primary 36 and a
secondary 38. Flow through the secondary in this case is controlled
by a flow deactivation valve 40 rotatably mounted in the passage
and controlled in a known manner by any suitable servo mechanism
indicated in general at 42.
As stated previously, the cross-sectional area of the primary
passage 36, the longitudinal extent of the dividing wall 34, and
the secondary passage volume between the valve 40 and the port
opening 24, is important. These will control the swirl of the
incoming air/fuel charge and the flow rate so that the engine will
operate efficiently at both maximum and minimum power ranges. In
this case, as seen in FIG. 2, fuel from the injector shown is
injected into the primary runner 36 for ignition by a conventional
spark plug 44. As will be described subsequently, the engine will
achieve maximum high speed power because the intake port opening 24
in this case is of the minimum restriction, free-breathing type,
due to the specific geometric configurations to be described that
control swirl in a desired manner. The engine also achieves a
maximum torque possible at low speed because in this case the
inducted swirl suppresses detonation while the cross-sectional flow
area maintains a minimum flow restriction. The engine also achieves
good combustion stability and burn rates at low load and idle
conditions because of the specific characteristics herein
described.
In this case, it will be seen in FIG. 1 that the dividing wall 34
extends directly to a point immediately adjacent and in line with
the valve stem 30 to positively divide the air inlet passage 32
into primary and secondary passages that are independent of one
another. Furthermore, the alignment of the dividing wall parallel
to the vertical axis of the valve stem 30 directs the incoming air
in the primary passage into the intake port opening in a tangential
manner to thereby induce a strong swirling motion of the mixture
inside the cylinder. The dividing wall 34, in this case, also
extends vertically the full depth or lateral extent of the air
inlet passage.
The primary passage 36 also is located outboard or laterally
furthest from the cylinder bore centerline compared to the
secondary passage so that when air is flowing through it alone,
extremely high levels of swirl can be developed in the
cylinder.
In order to provide the optimum swirl intensity, it is important
that the volume contained in the secondary passage runner 38,
between the deactivation valve 40 and the intake valve port
opening, be less than 15% of the cylinder displaced volume when the
deactivation valve is closed. When the valve is closed, this volume
is parasitic to the intake flow, and together with the flow in the
primary passage, must be drawn down to the incylinder intake
pressure before appreciable primary passage flow starts. A
secondary passage volume greater than the 15% value would result in
the draw-down flow from the secondary passage into the cylinder
when the intake valve opens diminishing the effect of the swirl
generated by the primary passage.
Other considerations of importance are the geometric relationships
of the end of the primary passage 36 with the intake valve
centerline and the cylinder bore wall 12. As best be seen in FIG. 3
, the orientation of the end 46 of the divider wall 34 that is
immediately adjacent the valve stem 30 is such that the angle
.theta. formed between the full line 48 extending from the cylinder
bore center C through the intake valve stem 30 and a second dotted
line 50 that is normal to the centerline of the dividing wall 34,
as extended through the center of the intake valve stem 30, should
be between 10.degree.-20.degree..
Also, the centerline 52(L) of the intake valve end of the primary
passage 36, as it is extended past the intake valve, should
intersect the line 48 that extends out to the bore 12, the distance
of this intersection point 54(P) from the bore center being between
0.75 and 0.85 of the bore radius R.
Another consideration is that the spark plug 44 should be located
in the combustion chamber as shown such that the incoming swirling
air charge will scavenge the electrodes of exhaust gas residuals
and thus provide optimum initiation of the ensuing combustion.
A still further consideration is that the cross-sectional area of
the primary passage 36 must be between 40%-50% of the total
cross-sectional area of the intake port opening. Any area ratio
less than this would be too restrictive for air flow and would not
give sufficient engine operating range when only the primary
passage is open, which is the case with many other concepts of this
sort that necessitate constant open and closing of the deactivation
valve with a consequent increase in engine calibration
difficulties, in order to obtain the necessary flow.
FIGS. 4, 5 and 6 show the cross-sectional shapes or configurations
of both the primary and secondary runners or passages 36 and 38 at
the various cross-sectional planes indicated in FIGS. 4 and 5. They
show the gradual change in the cross-sectional shapes, the primary
passage remaining in a semi-circular shape from Section 1 all the
way to the intake valve stem at section 13 where it rejoins the
secondary passage. This constant cross-sectional shape minimizes
the flow losses associated with the splitting of the main passage
32 into the primary and secondary runners and the rejoining again
at their downstream ends. It will be seen that the secondary
passage is blended from being approximately half-circular at the
intake valve to round at the location of the deactivation valve,
this being to facilitate the efficient manufacture and easy
assembly of the deactivation valve in high production volume.
FIG. 7 graphically illustrates the relationship between the
cross-sectional area ratio of the primary passage and the intake
port opening and important engine operating parameters. As can be
seen, this area ratio will minimize engine pumping work and
therefore maximize fuel economy by being unrestrictive even with
the secondary runner 38 closed. An area ratio greater than the
40%-50% stated above would not provide sufficient swirl to
stabilize combustion and enhance burn rates. An advantage of
maintaining the area ratio in this range is that it also keeps the
rate of pressure rise of the combustion below the threshold of
audible harshness. It additionally reduces the octane requirement
of the engine at low speed, maximum load conditions due to the
knock-suppression tendencies of swirling combustion.
In order to obtain the proper in-cylinder swirl intensity desired,
another critical relationship is the ratio of the total intake
valve port cross-sectional area, at a point one-half the diameter
of the intake valve head upstream from the valve head, to the area
of the outside diameter of the intake valve head. This ratio should
be between 0.55 and 0.65.
The primary passage 36 will remain open all the time and would
normally have the fuel injector located in it, as indicated in FIG.
2. The flow deactivation valve 40 would be closed at idle and
thereafter could be closed, modulated or incrementally opened at
part load conditions and low speed, high load conditions. It would
be fully opened at high speeds and loads. Maximum to minimum rates
of swirl would be obtained in a well-behaved fashion by modulating
the opening of the deactivation valve.
FIGS. 8 and 9 illustrate the relationships between swirl rate or
swirl intensity and air flow as a function of intake valve lift.
The ability to modify the flow and swirl characteristics of the
engine are independent of the overall air control or throttling.
Throttling of the overall engine air supply takes place upstream of
the deactivation valve.
EGR and PCV systems would be introduced into the primary passage 36
so as not to expose the deactivation valve 40 to possible deposit
build-up. The deactivation valve could be oriented horizontally or
vertically and be actuated by an inline shaft connecting mechanism
or linkages that could be used to operate a series of valves
simultaneously.
The operation of the invention is believed to be clear from the
above description and a consideration of the drawings, and,
therefore, is not repeated.
While the invention has been shown and described in its preferred
embodiment, it will be clear to those skilled in the arts to which
it pertains that many changes and modifications may be made thereto
without departing from the scope of the invention.
* * * * *